Association of chorioamnionitis and its duration with adverse maternal outcomes by mode of delivery: a cohort study

Abstract

Objective To investigate the association of chorioamnionitis and its duration with adverse maternal outcomes by mode of delivery. Design A retrospective cohort study. Setting Data from the Consortium on Safe Labor Study in the USA (2002–2008). Population Singleton deliveries at ≥23 weeks of gestation (221 274 assessed deliveries, 62 331 by caesarean section). Methods The association of chorioamnionitis, and secondarily the duration of chorioamnionitis estimated from intrapartum antibiotic use, with adverse maternal outcomes was analysed using logistic regression with generalised estimating equations, adjusting for age, parity, race, pregestational diabetes, chronic hypertension, gestational age at delivery, study site and delivery year. Analyses were stratified by vaginal versus caesarean delivery. Main outcome measures The composite adverse maternal outcome included: postpartum transfusion, endometritis, wound/perineal infection/separation, venous thromboembolism, hysterectomy, admission to intensive care unit and/or death. Results Chorioamnionitis was associated with higher odds of the composite adverse maternal outcome with caesarean delivery (adjusted odds ratio 2.31; 95% CI 1.97–2.71); and the association persisted regardless of whether a woman had a trial of labour, preterm delivery or maternal group B streptococcus colonisation. The most common adverse outcomes after caesarean section were postpartum transfusion (56.0%) and wound/perineal infection or endometritis (38.6%). Chorioamnionitis was not associated with adverse maternal outcomes after vaginal delivery. The duration of chorioamnionitis as the exposure did not alter the association between chorioamnionitis and adverse maternal outcomes. Conclusions Chorioamnionitis, but not the estimated duration, was associated with increased odds of adverse maternal outcomes with caesarean delivery. This finding has implications for care programmes to prevent maternal morbidity after a caesarean section complicated by chorioamnionitis. Tweetable abstract Chorioamnionitis, but not its duration, increases the risk of adverse maternal outcomes with caesarean delivery.

Risk Factors for Postpartum Maternal Infection Following Spontaneous Vaginal Delivery Complicated by Chorioamnionitis

“…15 In the Safe Labor study group, the increased incidence of adverse maternal outcomes was found to be significant in the setting of cesarean delivery but not vaginal delivery. 15 However, when individual outcomes were examined instead of the composite measure, there was a statistically significant increase in the frequency of developing endometritis (2 vs. 22%) or perineal wound infection (2 vs. 33%) in women who delivered vaginally without chorioamnionitis versus with chorioamnionitis. 15 The findings from our population present a similar picture, with 6.6% of women who had a vaginal delivery complicated by chorioamnionitis developing a postpartum infection, of which 30% was endometritis and 26% perineal wound infection.…”

“…The most recent ACOG Committee Opinion and the preponderance of data suggest that antibiotics may not be necessary after vaginal delivery. 11,14,15 While not all women develop infectious complications following chorioamnionitis, previous research has established an intrapartum diagnosis of chorioamnionitis as a risk factor for the development of postpartum infections. 4,8,15 A secondary analysis of data from the Consortium on Safe Labor (2002-2008) found Abbreviation: UTI, urinary tract infection.…”

“…11,14,15 While not all women develop infectious complications following chorioamnionitis, previous research has established an intrapartum diagnosis of chorioamnionitis as a risk factor for the development of postpartum infections. 4,8,15 A secondary analysis of data from the Consortium on Safe Labor (2002-2008) found Abbreviation: UTI, urinary tract infection. that 11.9 and 4.1% of women whose labor was affected by chorioamnionitis and delivered via cesarean section or vaginally, respectively, experienced adverse maternal outcomes including hysterectomy, postpartum transfusion, venous thromboembolism, endometritis, wound infection, intensive care unit admission, and death.…”

“…that 11.9 and 4.1% of women whose labor was affected by chorioamnionitis and delivered via cesarean section or vaginally, respectively, experienced adverse maternal outcomes including hysterectomy, postpartum transfusion, venous thromboembolism, endometritis, wound infection, intensive care unit admission, and death. 15 When chorioamnionitis was not diagnosed, 2.9% of women who delivered vaginally and 4.2% of women who delivered via cesarean section experienced these complications. 15 In the Safe Labor study group, the increased incidence of adverse maternal outcomes was found to be significant in the setting of cesarean delivery but not vaginal delivery.…”

“…15 When chorioamnionitis was not diagnosed, 2.9% of women who delivered vaginally and 4.2% of women who delivered via cesarean section experienced these complications. 15 In the Safe Labor study group, the increased incidence of adverse maternal outcomes was found to be significant in the setting of cesarean delivery but not vaginal delivery. 15 However, when individual outcomes were examined instead of the composite measure, there was a statistically significant increase in the frequency of developing endometritis (2 vs. 22%) or perineal wound infection (2 vs. 33%) in women who delivered vaginally without chorioamnionitis versus with chorioamnionitis.…”